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Differential effects of β‐adrenoreceptor antagonists on central and peripheral blood pressure at rest and during exercise
Author(s) -
Cockburn James A.,
Brett Sally E.,
Guilcher Antoine,
Ferro Albert,
Ritter James M.,
Chowienczyk Philip J.
Publication year - 2010
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1111/j.1365-2125.2009.03577.x
Subject(s) - blood pressure , medicine , heart rate , cardiology , propranolol , brachial artery , vascular resistance , cardiac output , placebo , peripheral , anesthesia , alternative medicine , pathology
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • At rest, β‐adrenoreceptor antagonists lower peripheral systolic blood pressure (SBP) but have less effect on central SBP. • Effects of β‐adrenoreceptor antagonists on central and peripheral blood pressure during exercise are unknown. WHAT THIS STUDY ADDS • This study shows that acute β‐blockade in healthy normotensive subjects markedly reduces peripheral SBP by ∼ 20 mmHg during moderate exercise but has no significant effect on central SBP. • The differential effect of β‐blockade on central and systolic blood pressure is not completely explained by reduction in heart rate. Beta‐blockade may blunt dilation of muscular arteries, influencing peripheral amplification during exercise. BACKGROUND Differential effects of β‐adrenoreceptor antagonists (β‐ARB) on central and peripheral blood pressure may relate to change in heart rate and/or vasodilator tone and thus be exaggerated during exercise. AIMS To examine acute effects of selective and nonselective β‐ARB on central and peripheral blood pressure, cardiac output and peripheral vascular resistance during exercise. METHODS Healthy volunteers ( n = 20, 18 men, 19–54 years) received propranolol 80 mg, bisoprolol 20 mg, and placebo 1 h before bicycle ergometry (50, 75 and 100 W each for 3 min) in a randomized, cross‐over study. Cardiac output was determined by pulmonary uptake of soluble and inert gas tracers (InnoCor, Innovision). Central systolic blood pressure (SBP) was determined from the late systolic shoulder of the digital artery pressure waveform (Finometer, Finopres). RESULTS At rest, both β‐ARB reduced brachial but not central SBP (compared with placebo). During exercise, β‐ARB reduced brachial SBP (reductions of 19.9 ± 4.3 mmHg and 23.2 ± 2.7 mmHg for propranolol and bisoprolol, respectively, at 100 W, each P < 0.0001) but not central SBP. The difference between peripheral and central SBP was reduced, relative to that during placebo, by 21.5 mmHg (95% confidence interval 8.8, 34.1) and 26.4 mmHg (18.1, 34.8) for propranolol and bisoprolol, respectively, at 100 W (each P < 0.01). There was no significant effect of β‐ARB on diastolic blood pressure or peripheral vascular resistance. CONCLUSIONS Despite reducing brachial blood pressure, acute β‐adrenoreceptor blockade in man at rest and during exercise does not reduce central blood pressure.